1. A Systematic Review of Yoga for Low Back Pain
M. Fahad Khan MD, MSc, MSPH; Simon Kim MD; Richard Kline PhD, MA; Germaine Cuff PhD, BSN
New York, NY
METHODS
BACKGROUND
1. Neuron. 2011 Feb 24; 69(4): 591–594.
2. N Engl J Med. 2013 Oct 24;369(17):1598-609.
3. Spine (Phila Pa 1976). 2012 Aug 15;37(18):1593-601.
4. J Rehabil Med. 2015 Feb;47(2):167-73
There has been a recent increase in interest in yoga as an alternative
therapy for chronic low back pain (CLBP) over the last decade. With
increasing trends to decrease overall opiate use for analgesia1
, recent
contamination issues in steroid manufacturing for spinal injections and
subsequent outbreaks of fungal meningitis2
, and more recent emphasis on
cost-effective therapies3,4
, yoga has become an attractive therapeutic option
for CLBP. The goal of this study was to provide an updated systematic
review examining the therapeutic effect of yoga on CLBP, focusing on
changes in VAS scores over time, in hopes to provide updated
recommendations on yoga as a therapy for CLBP.
Literature was sought from a query of 4 major databases (Medline, Embase,
Cochrane Library, PsycINFO) from their inception to June 2015 (See
Figure.) Studies were deemed appropriate for inclusion if the following
criteria were met: (1) a randomized control trial design, (2) focused on
patients with low back pain, (3) sought to study any physically active form of
Yoga, and (4) reported the measurement of patient specific outcome
measures (i.e. pain, functional status, disability score, quality of life
measure). RCTs that met criteria were analyzed for methodological quality
using the JADAD scoring scale. RCTs that met a score of 3 or more were
included for quantitative analysis evaluating changes in VAS scores over
time with yoga therapy.
Seventeen full text articles (15 study cohorts) were included in the systematic review.
The methodological strength of these studies ranged between a 1 and 4 on the Jadad
scoring scale. Of the 17 grouped trials, 15 individually reported author’s conclusions
supporting significant improvement in patient reported outcome measures in patients
receiving Yoga therapy as compared with other usual treatments, education, and other
non-invasive comparators. 8 studies with a JADAD score > 3 of which 7 were utilized
for group analysis. An analysis of grouped VAS scores yielded a finding consistent
with the majority of the studies included in the review.
Mean baseline VAS score before yoga therapy is 5.45 with range between 4.06 and
6.73 (n>30 across the 7 RCTs). Mean pain score improvements compared to baseline
following yoga-therapy showed 38.3% reduction at 1-2 weeks; a 35.1% reduction at
4-6 weeks; a 52.8% reduction at 10-12 weeks; a 56.2% reduction at 24 to 26
weeks; and a 49.2% reduction at 48 weeks. Plot of yoga’s effect on VAS scores over
time shown in Figure 2 shows the best fit line follows an exponential decay model with
the parameter of 0.396 (the inverse rate constant of 2.5 weeks) with a 95% confidence
interval of [-0.75, 0.867] and a p-value close to significance (p<0.1).
RESULTS
CONCLUSIONS REFERENCES
Current body of evidence is of mixed quality and requires filtering for high quality RCTs. Despite adequate numbers of
high quality RCTs and the heterogeneity in yoga forms across different populations, the effect of yoga seems consistent
in reducing VAS scores according to an exponential decay model. Due to lack of adequate studies examining the
immediate and long term effects of yoga on CLBP, future RCTs examining VAS scores to fill in existing data gaps are
needed to provide a clearer picture of the time-dependence of yoga’s effect. Functional aspect of pain was not assessed
in this review.
Study Selection Process
VAS Scores vs Time (weeks)